1. Field of the Invention
The present invention relates to locking mandrels and systems for installing flow control devices downhole in a well bore. The locking mandrel of the present system is particularly useful for releasably installing surface controlled subsurface safety valves within a landing nipple at a downhole location.
2. Description of the Prior Art
A wide variety of running tools, locking mandrels and landing nipples have been developed for installation and removal of flow control devices from downhole locations within a well bore. Examples of such devices are shown in U.S. Pat. No. 3,079,996 "Flow Control Devices for Flow Conductors"; U.S. Pat. No. 3,100,532 "Well Tools for Plugging a Well Flow Conductor"; U.S. Pat. No. 3,100,536 "Anchoring and Sealing Devices"; U.S. Pat. No. 3,207,222 "Locking Device and Running Tool Therefor"; and U.S. Pat. No. 3,208,531 "Inserting Tool for Locating and Anchoring a Device in Tubing". One limitation of each of the preceding devices is that they do not provide positive indication that the flow control device has in fact been secured or anchored at the desired downhole location. This limitation is of particular concern if the tubing string has several collar recesses and/or landing nipple profiles which can be engaged by the locking mandrel.
The present invention provides positive indication that the locking mandrel is anchored at a specific location within the tubing string. Control fluid pressure from the well surface which normally operates the subsurface flow control device is used to disengage the running tool from the locking mandrel after the locking mandrel is anchored at the desired downhole location. The above listed patents are incorporated by reference for all purposes within this application.